Re: [Qemu-devel] [PATCH v5 19/20] hw/arm/virt-acpi-build: Add PCIe controller in ACPI DSDT table

[Shannon Zhao]

On 2015/4/29 16:47, Igor Mammedov wrote:
> On Wed, 29 Apr 2015 11:12:04 +0800
> Shannon Zhao <address@hidden> wrote:
>
> > On 2015/4/28 23:54, Michael S. Tsirkin wrote:
> > > On Tue, Apr 28, 2015 at 05:13:10PM +0200, Igor Mammedov wrote:
> > > > > Here I need to set the value of buffer to 1 or 0, we could
> > > > > createbitfield, but if we want to set the value to non one or zero and
> > > > > the BufferSize is large, how could we do? CreateByteField? It's a little
> > > > > complex for user.
> > > > that's what one would have to do writing it in ASL if bits
> > > > are flipped on/off dynamically.
> > > >
> > > > In ASL you also can declare buffer with static initializer
> > > >
> > > >     Buffer (0x01) { 0x03 }
> > > >
> > > > and compiler is smart enough to set appropriate bits but it doesn't
> > > > allow you to do so with large values. For example:
> > > >
> > > >     Buffer (0x01) { 0xAABBCCDD }
> > > >
> > > > gives error:
> > > > Error 6139 - Constant out of range ^  (0xAABBCCDD, allowable: 0x0-0xFF)
> > > >
> > > > If one wants to manipulate specific fields in Buffer, ASL has
> > > > a bunch of CreateFOOField operators, so lets follow spec and use
> > > > API consistently to avoid confusion.
> > > >
> > > > BTW:
> > > > packaging value as int (even without prefix) is wrong since
> > > > its LE encoding will shuffle bytes and you won't get bits in
> > > > positions that you expect if value is more than 1 byte.
> > >
> > > I don't care about ASL, we are writing in C
> > > But AML is same:
> > > DefBuffer := BufferOp PkgLength BufferSize ByteList
> > > BufferOp := 0x11
> > > BufferSize := TermArg => Integer
> > >
> > > So really just a bytelist.
> > > We don't have any users for aml_buffer, maybe just add
> > > const uint8_t *bytes, unsigned len as parameters.
> >
> > Agree. It's consistent with the spec. If want to modify the value, could
> > use CreateFOOField.
> >
> > So use following fuction to initialize Buffer?
> >
> > /* ACPI 1.0b: 16.2.5.4 Type 2 Opcodes Encoding: DefBuffer */
> > Aml *aml_buffer(int buffer_size, uint8_t *byte_list)
> > {
> >      int i;
> >      Aml *var = aml_bundle(0x11 /* BufferOp */, AML_BUFFER);
> >      for (i = 0; i < buffer_size; i++) {
> >          build_append_byte(var->buf, *(byte_list + i));
> >      }
> >      return var;
> > }
> maybe
>
> Aml *aml_buffer_initialized(int buffer_size, uint8_t *byte_list);
> Aml *aml_buffer(int buffer_size);
>
> the second one is needed for implementing code like:
> Name(BUFF, Buffer(4){}) // Create SerialBus data buffer as BUFF
> CreateByteField(BUFF, 0x00, STAT) // STAT = Status (Byte)
> CreateWordField(BUFF, 0x02, DATA) // DATA = Data (Byte)
>
> and could reuse aml_buffer_initialized() to reserve space.

maybe we could use only one. For the uninitialized buffer we can pass 
byte_list as NULL and within aml_buffer check byte_list, if byte_list is 
NULL, just reserve space.

/* ACPI 1.0b: 16.2.5.4 Type 2 Opcodes Encoding: DefBuffer */
Aml *aml_buffer(int buffer_size, uint8_t *byte_list)
{
    int i;
    Aml *var = aml_bundle(0x11 /* BufferOp */, AML_BUFFER);

    for (i = 0; i < buffer_size; i++) {
        if (byte_list == NULL)
            build_append_byte(var->buf, 0);
        else
            build_append_byte(var->buf, *(byte_list + i));
   }

   return var;
}

> > > Would that be enough?
> > >
> > >
> > > > > > ifctx1 = aml_if(aml_equal(aml_arg(2), aml_int(0)));
> > > > > > aml_append(ifctx1, aml_store(aml_name("FNEN", aml_int(1)));
> > > > > > ...
> > > > > > /* create bit field for every supported function if supported */
> > > > > > ...
> > > > > > aml_append(method, aml_return(aml_name("RET")));
> > > > > >
> > > > > >
> > > > > > > > > > +    aml_append(ifctx1, aml_return(buf));
> > > > > > > > > > +    aml_append(ifctx, ifctx1);
> > > > > > > > > > +    aml_append(method, ifctx);
> > > > > > > > > > +
> > > > > > > > > > +    buf = aml_buffer();
> > > > > > > > > > +    build_append_int_noprefix(buf->buf, 0x00, 1);
> > > > > > > > > > +    aml_append(method, aml_return(buf));
> > > > > > > > > > +    aml_append(dev, method);
> > > > > > > > > > +
> > > > > > > > > > +    Aml *dev_rp0 = aml_device("%s", "RP0");
> > > > > > > > > > +    aml_append(dev_rp0, aml_name_decl("_ADR", aml_int(0)));
> > > > > > > > > > +    aml_append(dev, dev_rp0);
> > > > > > > > > > +    aml_append(scope, dev);
> > > > > > > > > > +}
> > > > > > > > > > +
> > > > > > > > > >   /* RSDP */
> > > > > > > > > >   static GArray *
> > > > > > > > > >   build_rsdp(GArray *rsdp_table, GArray *linker, unsigned rsdt)
> > > > > > > > > > @@ -318,6 +468,8 @@ build_dsdt(GArray *table_data, GArray *linker, 
> > > > > > > > > > VirtGuestInfo *guest_info)
> > > > > > > > > >       acpi_dsdt_add_flash(scope, info->flash_memmap);
> > > > > > > > > >       acpi_dsdt_add_virtio(scope, info->virtio_mmio_memmap,
> > > > > > > > > >                info->virtio_mmio_irq, info->virtio_mmio_num);
> > > > > > > > > > +    acpi_dsdt_add_pci(scope, guest_info->pcie_info);
> > > > > > > > > > +
> > > > > > > > > >       aml_append(dsdt, scope);
> > > > > > > > > >
> > > > > > > > > >       /* copy AML table into ACPI tables blob and patch header there */
> > > > > > > >
> > > > > > > > .
> > > > > >
> > > > > >
> > > > > > .
> > >
> > > .